It has previously been proposed to construct an insertion machine in which a plurality of pockets are secured to an endless transport mechanism, so that they operate in an endless path. The multi-sheet product, typically a folded substrate which, at the fold line, then forms two sheets, can be inserted in the pocket and, after insertion of a single sheet or a folded insert, the now combined multi-sheet product with the insert can be supplied to a suitable output transport mechanism. The insertion machine is designed to insert, for example, an advertising insert into an already folded newspaper. The already folded newspaper is opened by means of a blade and is retained in open position during the insertion process.
The insertion machine of this structure operates serially, in that one folded product is opened, and insert placed therein, and then is ready to be delivered. The operating speed, thus, is limited and, if a plurality of such structures are to be built and arranged in parallel, for example to increase the output speed, the size of the apparatus becomes excessive.
U.S. Pat. No. 4,295,643 describes an arrangement in which folded products hang by a hanger bar engaged beneath their back, the folded products hanging open. Inserts can be introduced into these folded products which, however, are also introduced serially so that the placement of inserts, if parallel operation is desired, again results in a structure of substantial size.